Symmetry of hR and Pseudo-hR Lattices

Abstract

Matrix methods for metric symmetry determination are fast, efficient, reliable, and, in contrast to reduction techniques, allow to establish simply all possible pseudosymmetries in the vicinity of higher symmetry borders. It is shown that distances to borders may be characterized by one or a few monoaxial deformations measured by parameter ε, which corresponds to the relative change in the interplanar distance. The scope of this chapter is limited to a careful analysis of rhombohedral or monoclinic deformations occurring in hR lattices.